Cooking equipment frequently causes an olfactory nuisance to the environment. This is particularly true for restaurants and industrial cooking equipment in the food industry, which discharge large amounts of air with a disagreeable and persistent odor.
The substances responsible for these bad odors are both numerous and not well identified: organic acids, esters, aldehydes of varying degrees of unsaturation, fats, etc. Even trace amounts can generate a disagreeable odor.
Numerous techniques for treating such discharges have been proposed to eliminate such odors. Particular examples among these are adsorption processes, for example using activated charcoal, catalytic oxidation processes, processes using solid state oxidising agents such as potassium permanganate, or oxidising agents in aqueous solution such as hydrogen peroxide, Javel water. Such processes are generally of low efficacy or are only effective for a very limited period which necessitates frequent replacement of the purifying agents and means that the treatment is very expensive.
Other processes require injecting substances which have a masking effect into the gas, but which do not actually eliminate the substances which are responsible for the bad odors. Such processes are both of low efficacy and expensive as large quantities of substances have to be continuously injected into the discharged gases.